IX 

 The Genus ITHYSIA (Hb) 



By J. W. H. Harrison, B. Se. 



As Mr. Prout has shown that the correct generic name of this 

 group is Ithysia, I am adopting it, in place of the more commonly 

 used Nyssia (Dup.) which includes in addition, the species I hâve 

 placed in my genus Poecilopsis. 



I had not intended to supplément my notes on the Bistoninœ, 

 published in the Entoinologist, for July 1910, until I had com- 

 pleted my work on the group ; but I hâve been compclled, by force 

 of circumstances, to publish the resuit of my investigations in 

 this genus. 



As the genus now stands in our lists, it includes the three 

 species Ithysia sonaria, I. alpina and /. grœcarïa or, as we now 

 call them, Nyssia zonaria, etc.; but I ûnd that there are four 

 species in the genus instead of the above three. Thèse are : 



Ithysia zonaria. (Schiff.). 

 /. alfina (Sulz.). 

 /. italica, sp. n. (Harrison). 

 /. grœ caria (Bdv — Staud.). 



To simplify the description of the species, I may, with advan- 

 tage, state hère the scheme, I hâve adopted in dealing with the 

 maies of the various hybrids I hâve reared in this family 



I look upon the forewings in the " idéal " species, as being 

 crossed by four lines which may, or may not, be obsolète in the 



